1. Field of the Invention
This invention relates to a label printer for issuing various types of labels.
2. Description of the Related Art
Supermarkets or suppliers, as a routine procedure, attach labels to various articles such as foodstuffs and daily necessaries to be sold, the labels each bearing an article code, supplier's name, price and other article information. FIGS. lA and lB show examples of the label. The article code is represented in the bar code form and the supplier's name and price are represented in the form of character or numeral. The label is issued from a label printer which receives externally supplied printing data, creates image data representing an image to be printed on labels in a dot matrix form based on the printing data, and performing a printing operation for the image data.
The conventional label printer includes a buffer memory, a character generator, a bar code conversion table, a frame memory and a printing section, for example. The printing data includes character and numeral codes corresponding to article information to be printed on a label, format data specifying the printing position, magnification, style and the like of data represented by the codes, issuing-number data specifying the number of labels to be issued and the like and is stored in the buffer memory. The printing data stored in the buffer memory is developed into image data by use of the character generator and the bar code conversion table. In the developing process, the character generator generates a character pattern according to the character or numeral code and the bar code conversion table converts the numeral code into a bar code pattern. Image data thus obtained is temporarily stored in the frame memory and then transferred from the frame memory to the printing section. The printing section prints an image on label paper based on the image data.
In a case where various articles which are packed in boxes for each kind are carried into an area in which the label printer is installed, the same type of labels corresponding in number to the articles packed in one box can be continuously issued. However, when various articles are packed in one box, it becomes difficult to continuously issue a large number of labels of the same type. FIG. 2 shows labels issued when the printing data is frequently changed according to the kinds of articles.
In the conventional label printer, image data is created by developing printing data each time the printing data is changed. The developing process of the printing data is complicated and takes a long time. Therefore, it is impossible to effect the printing operation for the printing data immediately after the printing data is changed, thereby lowering the average label issuing speed. This is the main cause of delaying the operation of attaching labels to various kinds of articles.